Important Port Number Http Imap MySQL DNS

FTP-data 20 Only if you use FTP on your server
FTP 21
SSH 22
Telnet 23
TCP/UDP Private Mail System 24
SMTP 25 Send mail
DNS 53 Domain Name Service
WWW 80 Standard web server port
POP3 110 For receiving email

IMAP 143 Internet Message Access PRotocol
HTTPS 443(80 HTTP) HTTP using SSL
IMAPS 993(143 IMAP) Secure IMAP

Pop3s 995(110-pop3)
SMTPS 465 (25 SMTP) Secure SMTP

mysql 3306
Squid - 443
DHCP Client 67
DHCP Server 68
IMAP3 220
RPC 1352 Remote Procedureal Call
LDAP 389 Lightweight Directory Access Protocol